Means for attaching metallic filaments to their carrier-arms.



No. 896,252. I PATENTED AUG. 18, 1908.

J. SGHILLING. MEANS FOR ATTAGHING METALLIG FILAMENTS TO THEIR CARRIERARMS.

APPLICATION FILED OCT. 10, 1906.

. a citizen of the German Empire,

-at Halensee, near Berlin, German haveinventedcertain .new and usefulImproved Means fdr Attaching Metallic Filaments toof which thefollowingis and of JOHANNES SOHILLING, HALENSEE, NEAR BERLIN, GERMANY.

IMEANS FOR ATTACHING METALLIC FILAIMENTS TO Tmm CARRIER -ARMS.

To all whom it may concern: 1 Be it known that I, JOHANNES ScHrL rne,and resid ng their Carrier-Arms, a description.

My present invention relates to incandescent electric lamps havingmetallic filaments, and has for its particular object to improve themanner of supporting said filaments, with a view ofsimplifying themanufacture obtaining a more reliable contact.

The invention will be fully described hereinafter and thefeatures ofnovelty pointed out inthe appended claims.

Reference is to be had to the'accompa- 'nying drawings in whichFigures-1 and 2 are perspective views showing two forms of my invention.

Filaments for incandescent electric lamps made from highly refractorymetals such as molybdenum, tungsten, tantalum, zirconium and the likehave a tendency to sag when incandescent, that is, thebow or loop of thefilament, if unsupported, will graduall lose its shape. On account ofthis pecu iarity, filaments of this character are now commonly supportedby suitable carriers, and according to one of the types now in use, acontinuous long filament is wound on the carriers, While according toanother type, a number of individual bows of comparatively short length,are employed, each of which bows has both ends secured to individualcarriers, the bows being connected in series.

v With .this latter construction there are as many carriers or supports,and as many oints, as there are bow ends, (with the exception of theterminals) or, in other words,

, almost twice as many supports, and almost twice as many joints, asbows. The connection at the joints has been effected by means of cementswhich have the defect of becoming brittle andweakened when they areexposed to a high heat upon the passage of an electric current throughthe filament. There is, therefore, danger of breakage at the joints,with the constructionnbove referred to. To avoid this defect, I havedevised a structure in which the adjacent ends of two neighboring bowsare connected with the same carrier by cement, so that the number ofjoints is reduced, and'furthermore, the

Specification of Letters Patent.

Application filed October 10, 1906. Serial No. 338,299.

are heated by the Patented Aug. 18, 1908.

connection from one be made exclusively through the carriers asheretofore, but the passage of the current will cause the adjacent orcontiguous ends of neighboring bows to bake or weld together,

so that even the breaking or dropping 013 of cement would not destroythe continuity of the filament.

In Fig. 1, a indicates the glass foot or stem in which are embedded theusual terminals or leads I) and to which is secured the central spindlec on which are mounted arms 01 nearest to the stem at, then two radiallyarranged sets of arms e, f, and finally a set'of carrier v arms 9 at thefree end of the spindle c The. filament comprises three bows, one ofwhich, h, extends from one of the terminals 6 to one w to the otherisnot of the arms d, passing onits way in contact withtwo' of the armse,two of the armsf, and

one of the arms 9. Another loop 7r extends in a similar manner from theother terminal b to the other arm (1. Finally the third filament textends from one arm d to the other,

passing on its way in contact with two of the arms e, two of the arms f,and oneof the arms g. rlt will, therefore, be seen that the outer. endof each carrier arm d serves as a connecting point, for the adjacentends of two of the bows, which ends are, therefore, quite close to eachother, so that when they assage of the electric current, they may -ba ietogether, welding automatically, as it were, and forming a,-joint whichis metal itse so that the fastening or cement ing at the ends-of thecarrier arms will practicallybe free from current, and thus will remaincooler than'when the entire current passes through it, as in the priorconstruction referredto, The joint is, therefore, much less liable tobreak. The construction practically as conductive as the l shown in Fi 2differs from that illustrated I by Fig. 1 on y by the omission ofthesecond set of supports f.

- It will be seen that the adjacent'cnds of two neighboring bows arecemented to the same supporting carrier arm; thus with three bows as inthe construction illustrated ends is equal to twice the number of bows,less two. I therefore, first, efiect a considerablesaving in the timeand labor required for the manufacture of the la'in second, as 5 hasalready been indicated, 1 o tain a much more reliable joint from thefact that the ad 'acent ends of the neighboring bows are rought intoclose juxtaposition, so that on the passage of the current the willbeweld- 10 ed together. The .joint is therefore much stronger and is alsoof better conductivity.

I claim as mg invention:

1. An incan escent electric lamp, provided 'with an internal"supporthaving carrier arms,

15 and a'ufilament consisting ofa lurality of bows engaged with saidarms, t e adjacent ends of two neighboring bows being secured to thesame carrier arm.

2. An incandescent electric lamp, provided with an internal supporthaving carrier arms, and a metallic filament consisting of a pluralityof bows engaged with said arms, the adjacent ends of two neighboringbows being secured to the same carrier arm and welded together. I

In'testimony whereof I afiix my signature in the presence of twowitnesses.

JOHANN SOHILLING.

Witnesses:

WOLDEMAR HAUPT, HENRY HASPER.

